pest control

Some weeks, it may seem like this blog is more about bugs than about plants. Isn’t gardening all about the plants? Well, it probably should be, but our gardens exist in the natural world, which is crowded with many kinds of life, including insects. Some of the insects are helper-insects, like pollinators and predators (“beneficials”). Other insects are destructive, eating our plants or spreading diseases across our landscapes (“pests”).

Some insects can be helpers as adults and pests in their larval stage. A lot of butterflies and moths are in this category. As adults, they pollinate flowers, helping plants to make fruits and seeds. As caterpillars (larval stage), they eat our plants. This dual life complicates a gardener’s decisions about how to manage caterpillars in the garden.

Which insects are “good” and which are “bad”? How can we know what to do when baby insects, like caterpillars, eat plants in our gardens?

Skipper butterfly on a late-summer zinnia. PHOTO/Amygwh

For me, the decision often comes down to whether the insect specializes on one kind of plant, especially if I am not planning to eat that plant. A lot of the skipper butterfly larvae eat turfgrass. Bermudagrass is not my most favorite plant, so I am not troubled when caterpillars are munching on the lawn.

However, the decision about how to manage pest insects in the garden could one-day disappear. You may remember the report last year of a study in Germany that showed a 75% loss of flying insects within the past few decades.

The authors of the study note:

The widespread insect biomass decline is alarming, ever more so as all traps were placed in protected areas that are meant to preserve ecosystem functions and biodiversity. While the gradual decline of rare insect species has been known for quite some time (e.g. specialized butterflies [9, 66]), our results illustrate an ongoing and rapid decline in total amount of airborne insects active in space and time.

A recent article in the Washington Post, “‘Hyperalarming’ study shows massive insect loss,” tells about another long-term study in Puerto Rico that shows the same trend. We are losing insects of all kinds, and in great numbers. Why should we care? The article offers a reason:

Thirty-five percent of the world’s plant crops require pollination by bees, wasps and other animals. And arthropods are more than just pollinators. They’re the planet’s wee custodians, toiling away in unnoticed or avoided corners. They chew up rotting wood and eat carrion.

To some gardeners, no longer having to worry about pest insects may sound like a dream come true. Sadly, the good and the bad go together. If we lose our pests, we also lose our helpers. This means we also lose a lot of good food and our “wee custodians”.

Like melons? They are pollinated by insects.

It may be possible for us to live on wind-pollinated crops, like wheat, corn, and beets, and on self-pollinated crops, like most of the beans. I don’t think we’d like that diet, though. In addition, being surrounded by rotting carcasses would make the situation extra-unpleasant.

While I don’t expect total losses of insects any time soon (or even in my lifetime), the thought of such a catastrophic loss of beauty and helpfulness is sobering.

What can we do to change the situation? Well, any action that supports insect life could help slow the decline. Try this:

plant more wildflowers to support native pollinators,

allow more diverse plantings in our yards, to provide more places to live for more kinds of insects, and

refrain (as much as we can) from using pesticide products in ways that kill multiple kinds of insects instead of just the one pest that is “bugging” us.

If you spend enough time in a garden, it will tell you about its gardener. The garden of my Mom and stepdad, Bill, mostly tended by Bill, is no exception. It is full of flowers, vegetables, and herbs,

The flowers are for beauty and for butterflies. Bill loved butterflies. Don’t tell my butterfly-conservation friends, but back when his eyesight was good (decades ago), Bill caught butterflies to use in art, posed with dried plants in box-frames.

Right now, the cosmos are providing nectar for migrating Monarchs, but Bill is not here to enjoy either the flowers or the butterflies, because my stepdad, Reverend Bill Shaw, passed away on Saturday, just a few days ago. When he and my Mom married, back in 1997, he and I became gardening buddies.

Bill, my Mom, and butterflies.

Bill’s Oklahoma garden always grew more vegetables than his household could eat. Tomatoes would take over the kitchen and peppers pile up in any bare spaces. The overabundance meant there was plenty to share.

The herbs are mostly for my Mom. They show that he loved her very much.

Bill’s garden reflects his preference for a well-ordered and tidy space. The plants are spaced far enough apart that there is room to work around them. His garden also shows that he could outsmart the groundhogs.

When the groundhogs first invaded, he tried all kinds of traps and baits that didn’t work. The groundhogs ate the plants from below, while underground, which made catching them more difficult. Finally, Bill bought some plastic food-grade barrels, sawed them in half, then sunk the halves into the garden. He planted much of his garden in those half-barrels, which kept out the groundhogs.

Tomato plants, safe from groundhogs in the half-barrel in-ground planters.

This planting strategy shows the creativity of the gardener. No groundhogs were harmed, but the plants were protected.

Back when Bill’s hearing was better, we would talk on the phone about our gardens. He was my main source of information about old-time garden practices. I was his source for information about new varieties and crop diseases.

I will miss Bill and our discussions about his latest plans for the garden.

Over the past couple of days, I have noticed that several flower buds on my zucchini squash plants don’t look healthy. The flower buds have stayed small and turned pale and droopy. Today, I finally took the time to REALLY inspect my plants. What I saw is a lot of bad news.

The holes in the flower buds and the holes in the stems could — possibly — be caused by several kinds of insects. However, the piles of pale green, round globs like tapioca, and the yellow globs too, are most likely frass (poo) from caterpillars.

Around here, a major cause of this kind of damage is squash vine borers. The adult moths lay eggs on the plants. Then, the tiny caterpillars that hatch out of the eggs eat their way inside the plant, where they eat and eat until they have killed the plant from the inside.

I pulled up two of my five zucchini plants to try to find the culprits/caterpillars. As I dissected the plants, this is what I found:

What are pickleworms?

Pickleworms, the caterpillars of a night-flying moth, are a common summertime pest in the South. They are pests I have seen before, but I have not seen such extensive damage to plants from their activity before. Who knew that they would gnaw right into a stem? Not me. At least, not until now.

If the damage had been from squash vine borers, I would have pulled up all five of the zucchini plants and called them an interesting late-summer experiment that I never need to repeat. Since the damage is from pickleworms, I am trying another option. That second option is the use of an organic-approved product for caterpillars.

Organic control for pickleworms

I have mixed up some “Bt for caterpillars” – the product at my house is Thuricide, but others are available – and I’ve sprayed it all over the stems and flower buds of the remaining zucchini plants and my little patch of cucumbers. The name “pickleworm”, if you haven’t already guessed, alludes to a fondness for cucumbers. Since I like cucumbers, too, it would be nice to bring any cucumbers that these plants make into my kitchen, without caterpillars inside.

I planted seeds for cucumbers the same day I planted the zucchini. With a time-to-maturity of 65 days, they seemed less likely than the zucchini to make a crop before the first frost, but they are another late-summer garden experiment. Since they have plenty of flowers on them, the odds look good that I might harvest a couple of cucumbers before the end of October.

This hope for cucumbers depends on me and the Bt. It will need to be re-applied every week, and after every rain, for the Bt to work well.

The little orange, dotted beetles that are eating my squash plants actually are in the ladybug family. Most beetles in the ladybug family do not eat plants; instead, they eat pests like aphids and whiteflies and are great helpers in our gardens. Mexican bean beetles and squash beetles, which look a lot alike, are exceptions. They are garden pests.

Right now, it is squash beetles in my garden, eating my squash plants.

It may look like ladybugs are eating my squash plants, but it is really squash beetles doing the damage.

How to identify squash beetles

The first big clue that they are not Mexican bean beetles is that they are on my zucchini, not on beans. Squash beetles eat plants in the squash family, like zucchini, squashes, and cucumbers. Bean beetles eat plants in the bean family.

Another is that their babies, also called larvae, have dark spines. The spines on Mexican bean beetle larvae are yellow, with dark tips as they get older.

Another clue is the method of eating. Both the babies and adults often gnaw a trench around the patch of leaf they are getting ready to eat. You may notice semicircular lines at the edges of damaged leaves.

One theory about why they do this is that the trenching prevents sap from running into the desired area. The sap may carry nasty chemicals that would interfere with the beetles’ eating.

Organic control of squash beetles

For now, I am hand-picking and smashing the beetles, both adults and larvae. The damage on my plants isn’t severe, and the number of beetles is low. Today, I found and smashed seven adults and one larva.

If the infestation gets bad enough that smashing is insufficient, there are a couple of organic-approved options to try. University of Connecticut agrees that hand-picking can work in small gardens but suggests that products containing spinosad might help if a beetle-damage gets very bad.

Another pest in my garden right now is armyworms

Armyworms have eaten most of the leaves in this patch of cleome.

I found armyworms in the garden today, too.

They were on both patches of cleome (spider flowers), and they haven’t left many leaves. When I realized what the pests were, I removed all the plants, with caterpillars attached, and stuffed them into a large bag.

That bag is now sealed up and ready for the municipal compost truck to pick up on Friday.

Armyworms can eat a garden to the ground in just a few days, which is why extreme steps are needed. If you see these in your garden, do not delay even one day in removing them!

Better news in the garden

First leaves on carrot seedlings are strappy and narrow; the next leaves are more feathery. PHOTO/Amygwh

Elsewhere in the garden, the carrot seedlings are sending up the “true” leaves that come after the first leaves. The first leaves that come out of a seed rarely look like the leaves on a mature plant.

For carrots, the first leaves are narrow and strappy. They are the ones that unfolded out of the seed, which is why the first leaves are often called seed leaves.

Do you see the seedling on the far right in the photo? The one leaf that is wider and more feathery gives a clue what the mature leaves will look like.

Also in the garden, there are tiny caterpillars on the pipevine plant. I planted the pipevine with these caterpillars in mind. If all goes well, a few of them will survive to become pipevine swallowtail butterflies, which are beautiful.

Some of the many kinds

The first variety I grew may have been ‘Italiko rosso’, a loose-leaf type with red leaf-veins running through its dark green leaves. Others have been ‘Pan di zucchero’, a less bitter variety that makes a head like Romaine lettuces, and ‘Catalogna’, an all-green loose-leaf type. Including chicory in our meals turns out to have been good practice for traveling in Italy, because at restaurants we visited, the cooked greens served with the second course of a meal often were chicory, not spinach.

Bringing home seeds from Italy isn’t allowed, but these two packets were emptied prior to travel. The packets are 7.5 x 4.5 inches — huge!

Radicchio, a heading-plant that is usually red instead of green, is also a kind of chicory. Endive and escarole are other forms of chicory that are familiar in the U.S.

These are all good to think about right now because they are cool-season crops that we can plant in our fall gardens. In general, the loose-leaf forms mature in 45-55 days, and so do most of the radicchios. Those can be planted in my area (zone 7b, with a first frost around Nov. 1) in a couple of weeks.

The heading type ‘Pan di zucchero’ takes 80 or more days to mature — it should already be coming up in the gardens of anyone nearby who wanted to grow it. Gardeners south of Atlanta, with later frost dates, still have time to get that variety started.

All of the above chicories are grown for their leaves, which are a lot less bitter in fall/winter/spring than in summer.

Chicory in the kitchen

I haven’t served chicory as a pile of cooked greens, Italian-style, at home, even when they haven’t been bitter. I am not a huge fan of cooked greens. Instead, I usually add raw leaves to a salad or to soups or sauces, where they end up cooked.

If I were going to cook chicory as a “mess of greens”, I would drop them into boiling water, let cook for about half a minute, drain off the water, then finish cooking in fresh water, just like for any other potentially-bitter green (collards, mustards). When we cook greens this way (because Joe does like greens), much of the bitterness goes down the drain with the water that we pour off.

The chicory in my garden right now

This year, I planted seeds for ‘Magdeburg’ chicory, a variety that has a bigger, tastier root for making chicory coffee.

The seeds went into the garden a few weeks before we left town, but the seedlings were not big enough for me to mulch their patch before we left for the summer. When we got back, the patch was a weedy mess. Among the weeds, though, were some chicory plants.

I weeded as carefully as I could but ended up pulling some chicory plants with the weeds in spite of the care. A few days later, yard-bunnies found the patch and nibbled it nearly to the ground. Wild yard-bunnies can be hard on a garden.

Deciding what to do about wildlife damage is not easy. There are many options for “pest control”, most of which don’t work. In the end, I poked some sticks into the ground near each plant, thinking that the sticks would be an annoyance for the bunnies.

As the plants regrew, the bunnies returned. Last week, I added a lot more sticks to the bunny-blockade. The more-crowded assemblage of sticks looks strange, but it seems to be working.

If all else fails and the bunnies are undeterred, I may be able to find a patch of wild chicory to use in making coffee. The bright blue flowers are easy to spot. The hard part will be finding a patch in an unpolluted place (not by a road, for example), where I can get permission to harvest the roots.

Chicory flowers in Italy are the same as those that grow wild here. PHOTO/Amygwh

While I’ve been walking outside our little town in Italy, missing my vegetable garden, I have paid attention to the local plants. On good days, I see a lot of flowers and pollinator-insects. At first, I thought the pollinators were all bees. Then, I looked closer. Many of them are actually flower flies, a different group of beneficial garden insects.

Flower flies are beneficial garden insects.

What are flower flies?

Flower flies really are flies, but a lot of them look like bees. It is possible that looking like a bee prevents some predators from eating them. I don’t know if that mimicry really works, though. We used to have a dog that ate carpenter bees when she could catch them. The stinging inside her mouth didn’t seem to stop her from catching and eating more.

Flower flies do not sting or bite, but they do eat nectar and/or pollen as adults. As they visit flowers to gather food, they pollinate the flowers. Flower fly babies (larvae) eat aphids and other small insects. These are definitely beneficial garden insects!

Organic gardens, in particular, rely on pollinators and predators in the garden to increase harvests and reduce pest problems. We can wait for our helpful predators (like flower flies, wasps and ladybugs) to eat the aphids, no spraying required!

Flower flies are also known as syrphid flies and as hover flies.

How can I tell which is a flower fly and which is a bee?

With only a brief glance, it is not easy to tell bees and flower flies apart. If you have the fortitude (and lack of bee-allergies) that allows you to look a little longer, you might see the difference.

Check the antennae

Flower flies have short, straight, stubby antennae. The antennae may be so short that they are hard to see. Bees have longer antennae, and their antennae are more likely to bend.

Check the wings

All flies have only two wings (one pair), and you can easily see them. One wing is on each side of the body.

Bees have fours wings (two pairs). The larger front pair of wings is easy to see, but the hind-wings can be hidden below the front pair. You might not be able to see that there are four wings.

Check the eyes

Eyes of flower flies are larger, and more on the front of their heads. Bee eyes are shifted a little to the sides of their heads.

Check the back legs

Flies do not collect pollen in clumps on their back legs. Some kinds of bees, especially our native, solitary bees, also do not collect and carry pollen on their back legs.

However, bumble bees and honeybees often store clumps of pollen on their back legs, to carry back to their colonies. If you see a bee-like insect that has pads of orange, or red, or yellow on its back legs, that is a good sign that the insect is some kind of bumble bee or a honeybee.

How can I attract flower flies to my garden?

University of California has published an easy-to-use table of plants that attract flower flies (see page 16). The table is deep within a document that is not super-easy to read, and not all the plants will grow well in the Southeastern US, but many will.

Here is a short list of plants that are known to attract and/or support flower flies to your organic garden, that I know will grow in the Southeastern US:

One of my most-favorite lines ever in a UGA Extension publication is about summer squashes. The line is in a table that lists recommended varieties for each type of crop. It says, for which varieties of summer squashes (including zucchini) to plant in the garden, “all are good and easy to grow.”

This line still makes me laugh. In a way, it matches my experience. In early summer the plants look great and produce plenty of flowers and small squashes. Unfortunately, it could also read “all are finicky and frustrating to grow”, since many summer-squash plants seem to drop into wilted piles of yellowing leaves in mid-summer, long before we have eaten too much squash. When I first started gardening in Georgia, I was lucky to get five or six good-sized squashes from a plant before it keeled over.

Southern Vs. Northern Experiences with Summer Squash

I am not the only Southern gardener to be troubled by a too-small squash harvest or plants that die too soon. However, Northern gardeners do not seem to have this problem. The complaint I hear from Northern gardeners is quite the opposite – they have mountainous harvests of zucchini and yellow squashes that keep coming all summer long.

Really, the complaint is one that doubles as a brag – their squashes are so very productive that, when the harvests begin, it is risky to leave your car windows open. The risk is that gardeners who have a superabundance of squash are likely to drop a large bag of squashes into the car as “a gift”.

Legend has it that over-squashed gardeners also will fill a bag with squashes, hang the bag on the doorknob of an unsuspecting neighbor’s home, ring the doorbell, and run. By the end of August, people are totally tired of squashes, especially zucchini.

I have never had so much summer squash and zucchini that I was not happy to find another one in the garden. Happily, as I have gained experience and understanding of what is going on in the garden, my plants survive longer and the harvests are larger. I have found that it is possible to have plenty of summer squash in the Southern garden, with a little planning.

Problems with Summer Squash in the Southern Garden

Squash Vine Borers

These are the cause of much anguish in the squash patch. The borers are larvae (caterpillars) of a day-flying moth that lays its eggs on stems of our squash plants. When the eggs hatch, the babies bore into stem, where they eat the soft part of the inside of the stem. The borers seem to not eat the toughest fibers, because one sign that borers have caused your squash plants to wilt is that the stem looks frayed. You may also see some frass (caterpillar poo), a golden-orange-brown, granular-looking mush, around or in the damaged section of stem.

What to do? If the plant is already a wilted mass of yellowing leaves, it may be too late to save the plant. If, though, you look at the lower part of a squash stem, see little holes in the stem and maybe a little frass nearby, but the plant looks otherwise healthy, it is not too late!

Step 1:

Locate the sharpest blade on your pocket knife and use it to make a long slit in one side of the squash stem. The slit should run lengthwise on the stem; it should start below where the damage seems to be and extend above the damaged area. Use the tip of the knife blade to pry the slit open, so you can look inside and find the squash vine borers. Use the knife tip to remove (or kill, depending on your philosophical stance on garden pests) the borers from the stem. You might find just one, but you might find a half dozen or more.

Step 2:

Saturate the inside of the stem with a product that contains Bt for caterpillars (Thuricide is the brand I have been using – bought a few years ago and still works), and spray up the length of the stem on the outside, too. If any borers are still alive inside the stem, the Bt for caterpillars (organic approved) should reverse that status fairly soon. If your Bt is powder form instead of liquid, do your best to fill the stem with the powder, and then liberally apply it along the outside of the stem.

Any Bt applied on the outside of the stem will wash away in the next rain or watering-event, so you might want to re-apply it a few times.

Step 3:

Mound up garden soil over the damaged section of stem. If you are feeling very industrious, you can try wrapping the damaged section with aluminum foil, but I find that just piling up some good soil over the damaged stem protects it from invasion by other pests. Also, squashes sometimes will send out new roots along buried sections of stem.

Step 4:

Consider the health-status of your plant. Summer squash in the Southern garden should be lush, with huge, dark green leaves. In my garden, the largest, fastest-growing squash plants survive squash vine borer damage much better than less-lush plants. If your plants are on the puny-side, side-dress with some organic fertilizer or a shovel-full of compost or composted manure.

Squash Bugs

Squash bugs look a lot like stink bugs as adults. As youngsters, they are called nymphs, and they move around in groups. The nymphs do not look at all like the adults, but if you see groups of insects scuttling around on your squash plants, they probably are squash bug nymphs.

Squash bug eggs on a leaf. PHOTO/Amygwh

These feed on the squash plants – leaves and fruits – and they can cause a lot of damage. An even bigger problem is that they can carry a squash disease called Cucurbit Yellow Vine, which can definitely kill your plants.

The adults and nymphs can be removed by knocking them into a tub of soapy water. It is a good idea, though, to check your plants for squash bug eggs.

You can use a piece of clear packing tape or a piece of duct tape to remove the eggs from your plants. Just press the sticky side of the tape to the collection of shiny eggs, remove the tape, fold it over, and smash the eggs inside the tape. Simple!

Removing all the eggs will help keep the population of adults and nymphs to a much lower level, which will limit the amount of damage they can do to your plants and reduce the risk of Cucurbit Yellow Vine.

Mildews

Summer squash in the Southern garden also is attacked by mildew diseases, both downy mildew and powdery mildew. If your plants die earlier in the summer, then these will not be a problem, because the mildews usually appear after mid-summer.

Downy mildew arrives at a slightly different time each summer in upper parts of the South. It can’t survive our winters, but it comes up from Florida where it survives just fine. If the petioles (leaf stems) are still standing up on your plants, but the leaves look brown and droopy, then downy mildew is a likely cause. There is no effective spray or treatment for downy mildew, but preventive care can help.

Leaf diseases like downy mildew (and powdery mildew) need leaf wetness to infect the leaves and grow. Keeping the leaves dry as much as possible, by careful watering, can delay infection. Increasing air-flow around the leaves, so they dry faster after a rain, also helps. Remove weeds as much as possible, and allow plenty of space between plants.

Also, healthy, well-grown plants get less disease than puny plants. Just like for squash vine borers, consider whether you might need to side-dress your plants with fertilizer or compost to improve their condition.

Powdery mildew becomes a big problem in warm, humid conditions. Since that pretty much describes several months of weather across the entire Southeast, it is a safe bet that powdery mildew will find your plants eventually.

Treating Mildews in Organic Gardens

For both downy and powdery mildews, the bacterial product Serenade, which is organic-approved, can slow down the rate of infection. It should be applied to plants every 7-10 days, before any sign of infection is seen. If you see signs of disease on your plants (mottled or brown spots on leaves, for example), it is too late to get much benefit from using the product.

In a couple of Cobb County community gardens, the use of Serenade has helped extend the “squash season” for local gardeners. If your squash patch has suffered from mildew attack in past years, you might consider trying the spray, but do not wait much longer to start. By July, infection may already have begun.

Another option is to spray with homemade products of either compost tea (one gallon of well-aged compost in a five gallon bucket filled with water, soaked for three days, then strained to use in a spray bottle) or a baking-soda spray, both of which can slow down an infection. Neither of these has been shown to work as well as Serenade (which works less well than chemical fungicides), but some gardeners like to try the DIY route first.

If you are a DIY gardener, this is the recipe for baking-soda spray recipe from one of my Rodale gardening books:

Dissolve 1 teaspoon of baking soda in a quart of warm water, with up to a teaspoon of dish soap or insecticidal soap added. Spray the leaves, including the undersides.

For both compost tea and the baking soda solution, apply to plants much more frequently than the Serenade.

Hoping for Plenty of Summer Squash from the Southern Garden

Summer squashes seem to be an essential vegetable in the South. They are the base of many favorite “church casseroles” – dishes that fill the tables at summertime potluck suppers and appear at your door in hard times. I don’t remember seeing squash-casseroles when I was growing up in Oklahoma, but I certainly have seen (and enjoyed) many since moving to Georgia. In the South, the squash harvest is important.

The garden/farm where Joe and I used to volunteer got around squash-plant losses by planting MANY squash plants over several weeks. Even when some plants died, more remained and produced squash. If the squash harvest didn’t look abundant enough, we just planted more.

In home gardens, this approach is not really feasible. Hence, the long blog post about upcoming problems with summer squash in the Southern garden.

Several weeks ago, while I was working in the garden, a battered, tattered black swallowtail butterfly flitted into my dill patch. While she was there she laid some eggs. Eventually, some of those eggs hatched, and then there were caterpillars in the garden, eating the dill.

They ate and ate. After awhile, some of the caterpillars disappeared. I assume other wildlife, such as birds, ate them. The last time I saw them, a few days ago, there were three left, fat and striped and still eating the dill.

PHOTO/Amygwh

They have all gone now, which means I can finally harvest the dill. The plan is to dehydrate most of it, for use this winter. I am thinking of using it on fish, in particular. It is also good in spanakopita, but I don’t eat cheese like I used to, even feta, so that recipe is no longer “in the rotation”.

What to do about caterpillars in the garden?

Even if these striped caterpillars were more voracious eaters, gnawing my dill plants down to little nubs, I probably would just make a note to plant a lot more next year. Accepting some insect-damage is part of the organic gardening way.

In addition, the world has been losing pollinators over at least the past couple of decades, probably longer. Even though butterflies are not our most effective pollinators, removing these with either an organic pesticide or a mechanical method like smashing would not be good for the future of food in the world.

Luckily, the caterpillars have left plenty of dill for us humans.

When other caterpillars in the garden eat so much that a plant is nearly bare of leaves, then control measures may be desired. As usual, the first would be to keep the adults, the butterflies, away from the plants completely. Draping small-meshed netting or a spun row cover on a support structure over the plants can keep adult fliers away (see post about cabbage butterflies and moths).

What else do these caterpillars eat?

These caterpillars are sometimes called parsley worms, because they eat many plants that are in the parsley family. If you guessed that one of those plants is parsley, you are right! Fennel and carrots are other garden plants in the same family, as is dill.

University of Florida has published a fact sheet about the Eastern black swallowtail butterfly, its lifecycle and ecology. The fact sheet includes a list of other plants these caterpillars will eat. Some are native plants, like mock bishop weed and water hemlock. Some are not native across the entire U.S., but have been introduced. One that many people will recognize is Queen Ann’s lace.

Where did the caterpillars go?

Surprisingly, Joe and I found a chrysalis way across the yard, in a flower bed, on Thursday. I almost never find these, so this one made my day.

Chrysalis of black swallowtail butterfly from 10May2018, in Georgia. PHOTO/Amygwh

The chrysalis is on a leaf of a hardy amaryllis, given to me by my mother-in-law many years ago.

My garden has been full of insect activity recently. There are lovely, tiny, metallic flies, some shiny black wasps, also tiny, and a few bees. I have also seen several ladybugs in the garden, plus some ladybug babies (larvae) and pupae (where larvae transform into adults).

Ladybug adults and larvae are voracious eaters of aphids. PHOTO/Amygwh

Which Species of Ladybug is in My Garden?

I am always happy to see ladybugs in the garden. They eat a lot of aphids. The adult ladybugs eat aphids, and the larval ladybugs eat aphids. For an organic gardener, this is a win-win combination!

Many of us would much rather rely on predators like ladybugs than use even organic-approved sprays.

When I decided to find out which ladybug is most common in my garden, I took a lot of pictures and then searched online.

My ladybugs mostly have about 16 spots on their backs, so it was easy to eliminate “two-spotted ladybug” from the list of possibilities.

Even better, university-based websites agreed that the black “M” shaped marking behind its head was a defining feature. It means my ladybugs are Asian multicolored ladybugs. At least, the adults are.

Apparently, this is a ladybug that tries to overwinter inside buildings; in winter it is considered a pest. In summertime, though, in gardens and farms, it is a big help in removing aphids from crops.

Why Are Ladybugs in the Garden, in Georgia, from Asia?

Apparently, various people brought these ladybugs to the U.S. on purpose, to help control pests like aphids and soft scale insects. According the University of Florida and the USDA, these ladybugs were released here many times in the past. The first time may have been a hundred years ago! The multicolored ladybug finally established permanent populations in the U.S. in the late 1980s to early 1990s.

Plenty of Work for Ladybugs in the Garden

My kale, especially, has been hit hard by aphids. Luckily, we have already eaten quite a lot of the kale ourselves. The current plan is to harvest the rest of the kale, wash it very well, and eat it soon. Any we don’t use on tonight’s pizza will get stashed in the fridge to use tomorrow.

Meanwhile, I have seen aphids on the milkweed — planted for the butterflies — and a few on leaves of the iris. Aphids also can be pesky in the fall; they are not just pests for the spring. My garden will probably feed a lot of ladybugs for many weeks to come.

Mexican Bean Beetles can strip all the green tissue off bean plants surprisingly quickly. If your organic garden is attacked by these pests pretty much every year, odds are high that you will see them again this summer.

Mexican bean beetles have stripped green tissue from most of leaves in this bean patch. PHOTO/Amygwh

How can you recognize these pests? The adults look a lot like ladybugs, only more orange or yellow. Their babies (aka “larvae”) are bright yellow, and look a bit like stubby, spiky caterpillars. (See the picture collage lower in this post.) The damage to the leaves, which become very brown as the beetles and their babies eat the green plant tissue, is the clue most gardeners notice first.

Having some strategies in place, before the bean beetles arrive, can help organic gardeners to harvest plenty of beans in spite of the coming pests.

Using Barriers to Keep Mexican Bean Beetles Off the Plants

For caterpillars like cabbage worms and loopers (babies of the cabbage moths and butterflies), we can use netting over our plants to keep the adult flyers away. If the adults can’t reach the plants to lay eggs on them, then we won’t have caterpillars on the plants.

For Mexican bean beetles, we can adapt this strategy by using a floating row cover instead of netting over the bean plants. The non-woven construction of the fabric means there are no holes for insects to sneak though. The row cover is lightweight and can be draped right over the plants, but it seems kinder to the beans to secure it over a support structure. The bean patch needs to be weed-free before the area is covered. Beans, in general, are self-pollinating; most varieties will make beans even when bees and other pollinators can’t visit the flowers.

Waiting for Parasites and Predators

There is a parasitic wasp that lays eggs inside the larvae of the bean beetles, just like there is a parasitic wasp that lays its eggs inside aphids. Sadly, the bean-wasp doesn’t seem to hang out in my yard, even though my garden gets attacked by Mexican bean beetles nearly every summer. Arbico Organics sells “mummies” (Mexican bean beetle larvae that contain wasp eggs/babies) as a bean-beetle-control for use on farms, but this is a very expensive option. It also is not really practical for home gardeners. Many of us are not growing even the minimum 70 square feet of beans per mummy recommended to make this work. It is nice, though, to know that there are insects working on behalf of farmers and gardeners to control these pests.

Spined soldier bugs and assassin bugs eat Mexican bean beetles, too. Some of these could already be present in your organic garden, but probably not enough. Certainly, there are not enough of these helpful predators in my own garden.

Stages of Mexican bean beetle infestation on bush beans, with a suggestion to alter timing of planting to harvest plenty of beans in spite of the beetles.

Insect-eating birds also can help reduce the population of bean beetles in the organic garden. In my bean patch, wrens move through the patch, hidden from my view below the canopy of leaves. All I can see is movement of the tops of the plants, until the wrens spring into flight after eating. It is great to know that these garden helpers are in action.

However, the birds seem to leave a lot of beetles uneaten. Maybe Mexican bean beetles are not very tasty.

Using Pest Control Products

In general, organic spray-type options for insect pests are not very effective, and options for beetles are worse. Spraying the undersides of the bean leaves with insecticidal soap (not an easy feat!) may kill the youngest larvae.

If you are desperate, try a product that includes Neem. Neither version of insecticidal soaps will have much effect on the adults, though.

You may have better luck than me at applying a spray to the undersides of leaves. If so, then insecticidal soap could slow down an infestation in your garden. Personally, I do not use a spray option.

For me, hand-smashing the larvae and eggs seems to slow down an escalating infestation about as effectively as using insecticidal soaps. So does knocking adults into a tub of soapy water, where they will drown. In other words, none of these options is super-effective.

Adjusting Your Planting Dates

This is the strategy that has given me the most abundant harvests. This strategy requires that gardeners plant their bush beans early — right around the estimated last-frost-date for their yard. This strategy allows gardeners to begin harvesting beans as soon as possible.

Mexican bean beetles don’t typically become abundant until sometime in the first half of July in my garden, and my estimated last frost is around mid-April. Planting near this date, when it can still be very cool, lets me bring beans to the kitchen beginning at the end of May, through all of June, and into early July, before bean beetles destroy the crop.

When the Mexican bean beetles have shifted from just feeding on leaves to also feeding on the beans, it is time (or past time!) to remove the crop completely from the garden. Be sure to clear it all away. Plant something else in this spot.

In 2-3 weeks, in another part of the garden, you can then plant a second crop of bush beans. In my garden, this second crop is untroubled by Mexican bean beetles. It does, eventually, get bean leaf rollers, but those do a lot less damage to the bean plants and they never eat the beans.

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